doyle



P 22, 1964 E. c. DOYLE 3,149,394

DEVICE FOR DETECTING DEFECTS IN THREAD Filed Aug. 9, 1962 KNVENTOR EUGENE C. DOYLE A'IT United States Patent 3,149,394 DEVICE FOR DETECTING DEFECTS 1N THREAD Eugene C. Doyle, Chattanooga, Tenn., assignor to Signal Thread Company, Chattanooga, Tenn., a corporation of Tennessee Filed Aug. 9, 1962, Ser. No. 215,943 1 Claim. (Cl. 28-64) This invention relates to a device for detecting defects in thread and more particularly to such a device which "will detect enlarged defects in thread and stop a textile machine using the thread.

The garment industry needs to have thread for making garments with as few breaks in the thread as possible. Most garment manufacturers estimate that each thread break costs them about 4 to cents. A device for detecting defects and stopping the textile machine is highly desirable in order to make it possible to analyze and classify the defects, then refer back to the spinning or twisting operation in an efiort to take such precautions as are necessary to remedy the cause of the defects.

Accordingly, one object of this invention is to provide a device for detecting defects and stopping a textile machine.

Another object is to provide such a device which is simple and inexpensive in construction and reliable in operation.

Other objects and advantages of the invention will be apparent from the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front elevation of one embodiment of my invention;

FIG. 2 is a side elevation, as seen from the right side of FIG. 1;

FIG. 3 is a rear elevation; and

FIGS. 4, 5 and 6 are partial front elevation views, showing the sequence of action of the curved guide slit in ejecting defective thread.

In the drawings, there is shown in FIG. 1 a front elevation of one embodiment of my invention which is mounted next to a spindle, not shown. For example, the device may be attached to a No. 50 Precision Winder, as by means of a bracket 1. A support member 2 is attached to the bracket 1 and to the support member 2 is fixed a blade or guide member 3 having a curved edge 4 which may, for example, be somewhat elliptical in shape. The member 2 has a lug 5 at one end thereof which is tapped to receive a thumbscrew 6, the end of which abuts against a movable blade or guide member 7. The member 7 has a curved edge 8 of the same contour and complementary to the curved edge 4 on the fixed member 3. The movable member 7 is attached, as by means of rivets 9, to a block or slide 10 slidable within a channel 11 bounded on the front by the rear surfaces of the member 3, the lug 5 and a solid portion 12 of the member 2. The block 10 is recessed, as at 13, to receive one end of a coiled compression spring 14, whose other end abuts against a surface 15 at the opposite end of the member 2.

In use of the device, the thumbscrew 6 is turned to force the movable member 7 against the spring 14 until the width of the open-ended slit, slot or space 16 between the curved edges 4 and 8, as measured by a feeler gauge, is approximately equal to the diameter of a thread or yarn T, which normally passes through the slit.

A stop lever 17 is normally biased in such a way as to stop the machine, as shown by the broken line position in FIG. 2. The thread T normally passes over thread ice guides 18 and 19 and thence over the stop lever 17, passing partially around the latter before going through the slit 16, at an acute angle with the blades or guide members 3 and 7, as shown in FIG. 2. In this manner, the thread T normally bears against the stop lever 17 and overcomes the bias of that stop lever, so that the textile machine may operate.

When a defect 20 larger than the diameter of the thread T is present in the thread, due to the shape of the curved slit 16 and due to the acute angle of the thread with the members 3 and 7, as shown in FIG. 2, the enlarged defect 20 rides up the slit and to the right, as shown in FIGS. 4, 5 and 6, until it passes entirely out of the slit and thereby is slid off the free end 17A of the stop lever 17. When this happens, the normal bias of the stop lever 17 is free to move the stop lever to the broken line position shown in FIG. 2, causing the stop lever to fall back against a stop wheel on the spindle, not shown, thereby bringing the spindle to a stop, so that the defect 20 can be either pulled off the thread or cut out of the thread and the ends of the thread can then be tied together with a weavers knot.

As indicated above, adjustment of the slit 16 is made for the diameter of the thread T, according to the gauge or size of thread to be wound. This adjustment is made by turning the thumbscrew 6 to move the movable blade 7 and the slide 10 against the force of the compression spring 14. When the width of the slit 16 is properly adjusted, as measured by a feeler gauge, the thread T is placed over the stop lever 17 and through the slit 16 between the blades 3 and 7.

Although this device was designed to operate on a No. 50 Precision Winder, it can be adapted to other types of winders by changing the type of brackets used.

A device made in accordance with this invention is designed primarily to detect slubs, knots, mixed yarn, etc., in plied thread yarn. Such a device not only detects these imperfections, but also stops the spindle so that the defect can be inspected without breaking the thread. Defects can be analyzed and classified and the proper steps can be taken to remedy the difficulty back in the spinning or twisting operation.

Many of the slubs can be pulled from the thread. The cut plies can be broken and a small weavers knot can be tied between the ends of the thread. Regular knots can be inspected and retied, if necessary. Flies are usually sheared or knocked oif without stopping the spindle.

A device made in accordance with this invention does not break the thread, as do previously used slub catchers. It avoids having in the thread many knots which are not necessary and which are undesirable and avoids the use of time and labor required for tying such knots. Moreover, it is much more sensitive to smaller knots or defects than are previously known slub catchers.

It will be apparent to those skilled in the art that various changes may be made in the invention, without departing from the spirit and scope thereof, and therefore the invention is not limited by that which is shown in the drawings and described in the specification, but only as indicated in the appended claim.

I claim:

A device for detecting enlarged defects in thread and stopping a textile machine comprising a stop lever biased to stop said machine,

a thread passing through said device normally bearing against said lever near a free end thereof to overcome said bias and two members having complementary curved edges forming an open-ended slit of uniform width through which the thread passes,

an enlarged defect in the thread being impassable through the slit and being guided by the curve out of the slit and oif the free end of the lever to release the lever and thereby stop the machine without breaking the thread,

one of said members being movable to adjust the width of the slit to the diameter of the thread.

References Cited in the file of this patent 

